Guide-sheave for elevators



(No Model.) 3 Sheets-Sheet 1.

. N. P. OTIS.

GUIDE SHEAVE FORELEVATORS.

Patented Oct. 24,1898.

atto'anugo (No Model. 3' 3 SheetsShe et 2.

N. P. OTIS. GUIDE SHEAVE FOR ELEVATORS.

No. 507,157. v Patented Oct. 24,1 93;

l E I awmm/lioz LL 104M202;

atto'owei o (No. Model.) 3 Sheets-Sheet 3.

N. P.- OTIS. GUIDE SHEAVE FOR ELEVATORS.

N0. 507,157. Patgnted Oct. 24, 1893.

UNITED STATES PATENT OFFICE.

NORTON P. OTIS, OF YONKERS, NEW YORK.

GUlDE-SHEAVE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 507,157, dated October24, 1893.

Application filed February 1, 1893. Serial No. 460,504- (No model.)

To all whom it may concern:

Be it known that I, NORTON P. OTIS, a citizen of the United States, anda resident of Yonkers, Westchester county, New York, have inventedcertain new and useful Improvements in Guide-Sheaves for Elevators, &c.,of which the following is a specification.

, My invention relates to that class of elevating apparatus in which thecable or cables from the winding drum must be deflected in passing fromthe drum to the pulley at the top of the well, and in which a travelingsheave is used for supporting the cable at its bend, and my inventionconsists in means fully set forth hereinafter whereby to auto maticallymaintain the traveling sheave and that portion of the cable between thesheave and the winding drum always in substantially the same verticalplane.

In the accompanying drawings, Figure 1, is a diagrammatic viewillustrating the ordinary arrangement of the drum, sheave and cable andsheave support. Fig. 2, is a front elevation in part section, of thedrum, sheave support, sheave and cable embodying myinvention. Fig. 3, isa side elevation. Fig. 4, is an enlarged detached view showing part ofthe friction device for the sheave shaft. Fig. 5, is a'view illustratingan arrangement when two traveling sheaves are employed.

In those cases in which it is necessary to deflect the cables that passfrom the winding drums in an elevator apparatus to the pulley at the topof the well and thence downward to the cage, it has been "customary tomake use of a traveling sheave sliding upon a shaft or bearing parallelto the axis of the drum. Where the said shaft is a plain shaft with thesheave sliding and revolving freely thereon, any unusual friction willresult in lost motion, so that the sheave does not fully accompany thecable in its lateral travel, andthe cable gradually acquires an angle tothe sheave and to the winding drum, causing it to slip from the sheave,or overlie the coils of the winding drum.

In some cases, as illustrated in the diagram,

Fig. 1, the'sheave A, turns and travels upon the stationary threadedshaft B, as the cable has been found that the use of such a threadedshaft does not remedy the evil, and that owing to slips and resistanceswhich cannot be prevented, the cable will be wound upon the drum to thefull capacity of the latter, before the sheave A, reaches the positionindicated by the lines m, Fig. 1, so that at the completion of thewinding, the sheave will be in the position indicated by the lines y,Fig. 1, with the cable at the angle shown, so that when the drumreverses its motion and the cable unwinds, imparting rotation to thesheave A, the latter travels toward the opposite end 1, is wound upon,or from the drum 0. It

(the left in the case illustrated) ahead of the plane in which the cableleaves the drum, and the sheave reaches the end of its travel before thecable is completely unwound from the drum, after which the cable canonly travel over the sheave by friction.

The object of my inventionis to insure such a travel of the sheave A,that it will always be substantially in the same vertical plane, as thatin which the cable travels from the drum, and to this end I providemeans whereby the said sheave may, if it gets out ing of the said shaft,except when the sheave A, is out of adjustment as hereinafter described.

One means of securing a frictional resistance of the turning of theshaft consists of a drum 20, keyed to one end of the shaft, and afriction strap or brake 3, preferably a steel brake band, passing aroundthe drum, connected at one end to a stationary pin 4., and provided atthe other end with a threaded rod 5, that extends through a hollowbearing 7, and carries one or more nuts 6.

In order to secure an elastic pressure of the band upon the disk, Iinterpose a yielding washer between the bearing 7, and the nut,

preferably in the form of a cup 9, through which the rod passes, andcontaining a hollow cylinder of rubber 8. By turning the nut, anydesired pressure may be applied to hold the shaft normally from turning.Upon the shaft turns the traveling sheave A, having one or moreperipheral grooves according as the cable is single or double, and withan expanded hub 12, containing a threaded bushing adapted to the threadsof the screw shaft B.

To the shaft B, are applied contact pieces, shown as two split nuts 13,14, each with a tightening bolt 15, so that the nut can be set to anydesired position upon the shaft, and then clamped thereto, andpreferably a check nut 16, is then brought to bear upon and furthersecure the split nut.

The opposite ends of the hub 12, and the inner faces of the split nuts,are preferably provided with engaging devices as pins or projections, sothat after the sheave A, is brought against either nut, or so that whenthe engaging devices of the sheave and either nut are brought incontact, the nut will turn with the sheave carrying with it the shaft B.

Assuming the parts to be in the position illustrated in Fig. 2, and thatthe drum begins to turn in the direction of the arrow, causing theportions (1, of the cable that pass around the sheave in front to moveupward, the sheave will be rotated, so as to travel toward the right, inproportion as the vertical plane of the cable also travels toward theright. If in the course of this travel there should be any slipwhatever, the lower portion of the cable would travel in respect to thedrum faster than the sheave travels in respect to the shaft B, so thatwhen the full amount of cable is wound upon the drum, the sheave insteadof being in full contact with the split nut, will occupy a position atthe left with the cable in the inclined position shown by the dottedlines w. It, now, the motion of the drum is reversed, and the sheavetravels back ahead of the unwinding of the cable, it will be brought incontact with the split nut 13, before the cable is completely unwound,so that as the cable is further unwound, and until the cable is in avertical plane co-incident with that of the sheave, the shaft will turnwith the sheave, so that there is no slipping of the cable upon thesheave. In case the lower end of the cable gains but little upon thatportion in contact with the sheave, the latter on approaching the nut14, will make contact with the said nut, and the nut and shaft will turnwith the sheave until the full amount of cable is unwound so that thereis no traveling of the cable upon the sheave. It will be seen that bythis means at least once in each travel of the cable between the extremepoints upon the drum, the cable and sheave will be brought into the samevertical plane, so that by these repeated corrections of anydisarrangements, the parts are kept practically in alignment with eachother, and that the said disarrangements can never be of any greatextent.

Where it is desired to make use of two sheaves, one for guiding eachportion of the cable, one sheave A, may turn upon the hub 12, of theother sheave A, as shown in Fig. 4, both being carried together. Anyother suitable means may be employed for causing the shaft B, to turnwith the sheave when the latter is moved by the cable in advance of thelower portion of the cable, that shown being a simple and effectivemeans for such purpose.

As the drums of elevator apparatus are generally of uniform size, but asthe extent to which the cable is wound upon a drum will depend upon theheight of the building, the devices for limiting the movement of thesheave independent of the shaft must be adjustable to permit the sheaveto travel to a greater or less extent upon the shaft. This adjustment issecured by employing the adjustable nuts 13 and 14, with means forsecuring them in place after adjustment.

Without limiting myself to the precise coustruction and arrangement ofparts shown, I claim- 1. The combination with the drum and cable of anelevator apparatus, of a threaded shaft, a sheave turning and travelingon the said shaft in contact with one portion of the cable, and meansfor automatically engaging the shaft with the sheave when the latterturns after reaching the limit of its traveling movement, substantiallyas set forth.

2. The combination, with the drum, cable and sheave, of a screw shaftupon which the sheave turns and travels, said shaft supported to turn inits bearings, means for applying a frictional resistance to the turningof the shaft, and means for automatically turning the shaft with thesheave when the latter turns after reaching the limit of its movement,substantially as set forth.

3. The combination of the drum, cable and sheave turning and travelingon the shaft, of bearings supporting the shaft to permit the same toturn therein, means for applying frictional resistance to the turning ofthe shaft, and nuts or contact pieces upon the shaft arranged to be incont-act with the sheave as the latter reaches the limit of its movementin each direction, substantially as set forth.

4. The combination with the drum, cable, sheave and screw shaft, ofcontact pieces adjustably mounted on the shaft, means for securing thesame after adjustment, and means for applying a frictional resistance tothe turning of the shaft, substantially as set forth.

5. The combination with the drum, cablenuts, and a bearing supportingthe bands, substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

NORTON P. OTIS.

Witnesses:

HENRY L. BRANT, WM. L. RICKARD.

